How redundant information can help overcome bias (joint with Nicolás Figueroa and Rubén Jara) (previously circulated as "Communication through biased intermediators")
Abstract: An organization with access to data delegates its empirical analysis on a possibly biased expert. We find that, by adding redundant information and privately manipulating the data (e.g., by secretly switching data entries), the organization is able to completely neutralize the bias of the expert; it is as if the expert is unbiased. We discuss how our results can be used to increase the transparency of empirical research with particular emphasis on the medical research over the effects of certain drugs.
Assignment mechanisms with state-independent preferences and independent types (online appendix)
Abstract: I study a general mechanism design problem without transfers under two assumptions: that agents have state-independent preferences and statistically independent types. I characterize optimal mechanisms for the one-agent and multiple-agent cases, discuss the value of commitment power for the decision maker and prove a comparative statics' result. As an application, I consider the optimal design of peer-review contests when jurors are biased. I argue that quotas, where each academic field is assigned a fixed number of prizes, are not optimal, and that asking reviewers to review applications from other fields may actually increase the expected quality of the prize recipients.
Can impartial peer-review mechanisms replace external reviewers?
Abstract: The increase in the number of academic competitors for grants and conferences makes it unfeasible to continue to rely exclusively on external reviewers for peer evaluation. An alternative is to ask applicants to rate each other using impartial mechanisms which eliminate the incentives to misreport of self-interested applicants. I introduce the reliable subset mechanism and argue that, for most academic contests, this impartial mechanism performs similarly to using external reviewers, provided the applicants are as capable of generating accurate reviews. I then show that external reviewers are rendered unnecessary altogether whenever evaluations of the same applicant are strongly correlated.
The dynamics of religious conversion: Theory and Evidence (joint with Akwasi Ampofo, Umair Khalil and Laura Panza)
Abstract: We develop a theoretical model of religious conversion in which potential adherents face changing payoff structures, spiritual or instrumental, triggered by the arrival of a new religious movement, the conversion of monarchs, or other shocks that alter the relative returns to conversion. Coupled with non-linear private returns in the share of co-religionists and intergenerational transmission of religious beliefs, our model yields multiple, stable steady-states in the community's religious composition. We use this model to rationalize the spread of Islam in West Africa post-1500. The Atlantic slave trade altered payoffs in favor of Islam because Muslim rulers offered a de facto protection from enslavement, but only to their co-religionists. This created strong incentives for conversion among non-Muslims in regions exposed to slave raiding. Using newly compiled historical data alongside contemporary survey-based measures of Islamic presence, we show that communities under Islamic rule during 1500-1900 and exposed to Atlantic slavery exhibit persistently higher Muslim presence both after the end of slavery and today.